diff --git a/_DominikNotes/2022-04-12_anja_stefanski.md b/_DominikNotes/2022-04-12_anja_stefanski.md new file mode 100644 index 0000000000000000000000000000000000000000..139597f9cb07c5d48bed18984ec4747f4b4f3438 --- /dev/null +++ b/_DominikNotes/2022-04-12_anja_stefanski.md @@ -0,0 +1,2 @@ + + diff --git a/_DominikNotes/notes_proteomics.md b/_DominikNotes/notes_proteomics.md new file mode 100644 index 0000000000000000000000000000000000000000..787b59552742759d6b92ff873193f13b14f21d69 --- /dev/null +++ b/_DominikNotes/notes_proteomics.md @@ -0,0 +1,54 @@ + +# proteomics notes + +> adapted from: https://training.galaxyproject.org/training-material/topics/proteomics/slides/introduction + +- [glossary](#glossary) +- [sample-prep](#sample-prep) +- [LC](#lc) +- [LC-MS/MS - liquid chromatography tandem mass spectrometry](#lc-msms---liquid-chromatography-tandem-mass-spectrometry) +- [data analysis](#data-analysis) + +## glossary + +- LFQ = label-free quantification + +- explorative / shotgun proteomics (untargeted) + - DDA: data dependent acquisition + - DIA: data independent acquisition + +## sample-prep + +1. protein extraction +2. reduction (of disulfide bridges) and alkylation (of cysteins) + - ensures that tryptic peptides are separated from each other and allows their mass based identification +3. tryptic digestion: Trypsin cleaves the amino acid sequences C-terminal of arginin and lysine +4. desalting: clean up step to protect the instrument from contamination and clogging + +## LC + +- separates peptide mixture according to hydrophobicity +- reduces sample complexity and gives the mass spectrometer time for the measurement +- acidic LC buffer charges the peptides positively at their N-terminus and the basic lysin or arginin amino acids on the C-terminus +- electrospray ionization: + - LC column is directly connected with ion source needle + - high voltage and heat are applied to evaporate the ionized peptides into the gas phase + - mass spectrometer mass analyzer separates peptides based on their mass-to-charge ratio + +## LC-MS/MS - liquid chromatography tandem mass spectrometry + +- While sample elutes from the LC column, thousands of mass spectra are acquired +- First, a mass spectrum of all peptides: **MS1 spectra** +- From MS1 spectra the N most abundant peptide peaks are determined. These topN peptides get fragmented. N is typically between 3 and 20 + - filter unit of the mass spectrometer (a quadrupole) allows only these peptides to pass + - One after the other is selected in the filter unit and then fragmented by collision with neutral gas molecules. This fragmentation breaks the peptide bonds and generates peptide fragments + - The peptide fragments are measured again via the mass analyzer and detector: **MS2 spectra**. + - After all topN peptides were fragmented and measured, another full MS1 mass spectra is acquired. + - MS1 and MS2 spectra are acquired in this way during the elution of the sample from the LC. + +## data analysis + +1. peptides are identified via their MS2 fragmentation spectra +2. From these peptide identities the corresponding proteins are assembled +3. The MS1 spectra are used for peptide quantification +4. Peptide quantities are summarized into protein quantities \ No newline at end of file diff --git a/_DominikNotes/notes_software.md b/_DominikNotes/notes_software.md new file mode 100644 index 0000000000000000000000000000000000000000..73b1b835db175dbdfb03b190a7aa80ee7a95ac58 --- /dev/null +++ b/_DominikNotes/notes_software.md @@ -0,0 +1,32 @@ + +# Notes on proteomics software + +- [MaxQuant](#maxquant) + - [installation](#installation) + - [tutorial](#tutorial) + - [galaxy](#galaxy) +- [rawrr package](#rawrr-package) +- [pyteomics](#pyteomics) + +## MaxQuant + +### installation + +### tutorial + +- hot to run maxquant on linux: https://youtu.be/KHdvO1M85VM +- requires windows... + +### galaxy +- https://training.galaxyproject.org/training-material/topics/proteomics/tutorials/maxquant-label-free/tutorial.html + + +## rawrr package + +- The rawrr R Package: Direct Access to Orbitrap Data and Beyond +- https://pubs.acs.org/doi/10.1021/acs.jproteome.0c00866 + + +## pyteomics + +- https://github.com/levitsky/pyteomics \ No newline at end of file